New (e,2e) Studies of Atomic and Molecular Targets

We report new coplanar (e,2e) measurements characterised by large energy transfer and close to minimum momentum transfer from the projectile to the target. Ionisation of the two-electron targets He and H2 is investigated under these particular kinematics. The experimental data are compared with the predictions of the most elaborate theoretical models. The obtained good agreement motivated us to extend our research to the case of more complex targets such as Ar. Comparison with the most elaborate models in the case of multi-electron targets is excellent. Destructive and constructive interference effects in the case of H2 are observed and discussed

Semiclassical model for calculating fully differential ionization cross sections of the H2_2 molecule

Fully differential cross sections are calculated for the ionization of H$_2$ by fast charged projectiles using a semiclassical model developed previously for the ionization of atoms. The method is tested in case of 4 keV electron and 6 MeV proton projectiles. The obtained results show good agreement with the available experimental data. Interference effects due to the two-center character of the target are also observed and analyzed.Comment: 11 pages, 4 figure

Coincidence Angular Correlation in Electron Impact Single or Double Ionisation of Atoms and Molecules

Experimental results obtained with our multi-parameter multi-coincidence spectrometer are presented for the (e,3e) double ionisation of Ar and (e,2e) single ionisation of small molecules. The (e,3e) measurements are discussed in terms of competition between the two double ionisation processes present under the chosen kinematics, and qualitative conclusions are given. The results for the ionisation of H2 and the outer orbital of N2 are compared with the predictions of the most elaborate available theoretical models for description of the molecular ionisation process. Overall reasonable agreement is observed and tentative interpretations for the discrepancies are discussed

Grazing Fast Atom Diffraction (GIFAD): an advanced real−time surface characterization technique

International audienc

Real−time monitoring of thin film growth by HiPIMS using Grazing Incidence Fast Atom Diffraction (GIFAD)

International audienc

Grazing Fast Atom Diffraction (GIFAD): an advanced real−time surface characterization technique

International audienc

Real−time monitoring of thin film growth by HiPIMS using Grazing Incidence Fast Atom Diffraction (GIFAD)

International audienc

Croissance sous−vide de couches minces de MAPbI : évidence pour une phase hexagonale

International audienc

Investigation of the (e,2e) single ionisation of He and Ar at large energy loss and close to minimum momentum transfer

International audienc

Experimental and Theoretical Confirmation of the Role of Higher Order Mechanisms in the Electron Impact Double Ionization of Helium

Our recent measurements (Lahmam-Bennani et al 2010 J. Phys. B: At. Mol. Opt. Phys. 43 105201) of the (e,3-1e) four-fold differential cross sections (4DCS) for double ionization (DI) of helium are extended here to a wider range of ejected electron energies and very asymmetric energy sharing. Previous observations of large angular shifts in the experimental 4DCS distributions with respect to the momentum transfer axis are once again reproduced by the new measured data. Moreover, a comparison of all the data sets with the kinematical analysis previously given and with two newly developed non-first-order theoretical models for DI-namely the two-step 2-Monte Carlo event generator (TS2-MCEG) and a second Born approximation (B2)-confirms our interpretation which allows the observed shifts and the existence of structures in the intensity distributions to be mostly related to the second order, TS2 DI mechanism, which is shown to predominate over the first-order \u27shake-off\u27 (SO) and \u27two-step 1\u27 (TS1) mechanisms under the present kinematics